Safety device for platen printing-presses.



M. ROGKSTROH.

SAFETY DEVICE FOR PLA'IEN PRINTING PRESSES.

APPLIOATION FILED DEO.21, 1912.

1,093,079. Patented Apr. 14, 1914.

4 SHEETS-SHEET 1.

% i I i w 7% 3 \vLLAuuA I'LANOGRAPH CO.,WAS1HNGTON. D, C

'Fioz.

M. ROGKSTROH.

SAFETY DEVICE FOR PLATEN PRINTING PRESSES. APPLICATION FILED DEC. 21, 1912.

Patented Apr. 14, 1914.

4 SHEETS-SHEET 2.

COLUMBIA PLANOGRAPH CCI-AVASHINGTON. Dv c.

M. ROGKSTROH. SAFETY DEVICE FOR PLATBN PRINTING PRESSES.

APPLICATION FILED D110. 21, 1912. 1,093,079 Patented Apr. 14, 1-914.

4 SHEETS-SHEET 3.

COLUMBIA PLANOGRAPH CO..WASHINCITON, n a

M. ROGKSTROH.

SAFETY DEVICE FOR PLATEN PRINTING PRESSES.

APPLICATION FILED DBO. 21, 1912.

1,093,079, v Patented Apr. 14,1914.

4 SHEETS-SHEET 4.

COLUMBIA PLANOGRAPH co.. WASHINGTON. n. C

MAJI ROGKSTROH, OF KLEIN SEDLITZ, NEAR PIRNA, GERMANY.

SAFETY DEVICE FOR PLATEN PRINTING-PRESSES.

Specification of Letters Patent.

Application filed December 21, 1912.

Patented Apr. 14, 1914.

Serial No. 738,023.

To all whom it may concern:

Be it known that I, MAX RooKs'rRoH, manufacturer, a citizen of the Kingdom of Saxony, in the German Empire, residing at Villa Liitzow, Klein Sedlitz, near Pirna, Germany, have invented certain new and useful Improvements in Safety Devices for Platen Printing-Presses, of which the following is a specification.

My invention relates to protective devices for platen-presses comprising a stationary platen and rocking form.

In my patent application filed simultaneously herewith a protective device is described for platen-presses comprising automatic means for throwing the machine out of gear, in which device a guard plate or similar member is arranged, instead of a bow or frame, and covers over the danger-- ous gap between the platen and bed and simultaneously serves for disconnecting and braking the machine, in the case of danger, in consequence of its change of position brought about by the hand of the workman.

A primary object of this invention is to provide a similar protective device for those platen presses in which the platen is stationary, while the form, mounted on the head of the press, rocks up and down.

In the hereinafter described embodiment of my invention I employ, instead of the guard plate, a protective grid, the object of which is to cover over the opening between the form and platen when the head of the press descends, in order that the hand or other part of the body of the workman cannot readily pass between the form and the platen; should this nevertheless occur, however, owing to carelessness on the part of the workman, the machine is stopped by the action of the protective grid on the disconnecting device. In this manner, in the machine according to my present invention the dangerous gap between the form and platen is covered and insertion of the hand prevented, and the machine is also thrown out of gear as soon as the hand is carelessly left on the platen, as is the case in the machine disclosed in my simultaneous application.

The device described in my simultaneous application cannot be at once applied to machines comprising a stationary platen; in this type of machine it is necessary that the protective grid or other guard be already in its lowest position, thus bearing on the platen, before the form has reached the face of the platen, To this end, according to the present invention when the protective device moves downward it leads in front of the downwardly moving head. This may be arranged in many ways; for example, the mechanism for the upward movement of the protective grid or other guard may be influenced by a cam which is actuated by the driving mechanism of the head, 6. g. by the coniiectingrod. It is preferable kinematically to couple the protective device in its lowest position with the head of the press in such manner that when the head moves upward, the protective grid is at once driven, in order not to lose time for the new insertion.

One illustrative embodiment of my invention is represented by way of example in the accompanying drawing, wherein Figure 1 is a side elevation showing a platen-press, comprising a stationary platen and my improved uard, in the highest position of the presslead with the protective grid raised; Fig. 2 is a like view showing the press with the head partially lowered; the grid has already taken up its lowest position; Fig. 3 is a like view showing the press in a position in which an accident may occur, the protective grid not bein able to occupy its lowest position; and Fig. 4 is a like view, enlarged, showing the press with the head bearing on the platen; the protective grid remains located in its lowest position on the disconnecting and braking device.

Referring to the drawings, the press-head a carries approximately vertical guides b in which rods 0 can slide u and down; the protective grid, plate or the like (Z is carried by these rods. To the lower end of one of the two rods 0 is pivoted a lever e which in turn is pivoted to one arm of a two-armed lever f. The fulcrum of this lever f is in a bearing h mounted on the head a. The other arm of the lever f carries an anti-friction roller z' for running from time to time 011 a cam j which is clamped to the connecting-rod 70. This cam has a projection for rocking the two-armed lever f and with it the grid cl into their highest positions, while the recess in the cam allows the lever f and the grid (Z to occupy their lowest positions, a. 6. those in which the grid closes the open ing between the platen and the form. The shape of the cam j is such that the grid d is Ltd in its lowest position before the connectingrod has reached its lowest position and when the press-head has traveled about half its path, as shown in Fig. 2.

The grid and the two-armed lever f are coupled with the connecting-rod at the beginning of the upward movement of the latter by a recessed catch Z which at the end of the downward movement of the connect ing-rod it, bears against the end of the short arm of the two-armed lever fand locks this, so that this lever is held in its elevated position during the upward movement of the connecting-rod. Vhen the lever f is locked by the catch Z the latter is held against an adjustable screw m carried by the connect ing-rod or by a member attached thereto.

The described device operates as follows :The press-head rocks a considerable distance, while the connecting-rod, on the contrary, remains approximately vertical; the relative movement of the two is used for moving the cam j to the left and to the right. The grid (Z and the lever 6 being located in the position shown in Fig. 4, when the press-head is elevated (Fig. l) the twoarmed lever f occupies its highest position, the roller 2' being located on the top of the projection of the cam j, as shown in Fig. 1. Now when the connecting-rod 7.; and with it the head a moves downward, the roller 2' slides on the cam and, when the form of the press-headis still about 120 mm. from the platen, arrives into the recess in the cam, whereby the two-armed lever j likewise 0ccupies its lowest position and the grid (Z bears on the disconnecting lever n (Fig. 2) which is connected with the disconnecting rod 0 by two links p, q pivotally connected together. The lever 1 fulcrumed at s, is pivotally connected at t with the disconnecting rod 0 which disconnects the machine in known manner and is also able simultaneously to operate the brake. The grid now remains with its lower part bearing on the lever 02, while the connecting-rod 7s and the press-head move farther downward. The two-armed lever f is hereby rocked farther upward, however, (Fig. 4t) and the pivot of the roller 7 or a similar member on the free arm of the lever f is locked in the recess a of the catch Z which bears against the screw m. The catch is fixed in its position when the press-head rises owing to the pivot of the roller z being pressed firmly into the recess a of the catch Z by the weight of the protective grid. The catch is released in the highest position of the head by the cam j rocking the short arm of the lever f down ward, whereby the catch is released and falls owing to its own weight, so that when the press-head rocks downward the roller 2' runs freely on the cam. WVhen the press works normally (of. Figs. 1, 2 and 4) the releasing mechanism a, p, g, r, s, 0 of the disconnecting and braking device is in such a position that the sto 11 on the connectingrod L can pass freely by the levers p and g. If an obstruction, e. g. the workmans hand, arrives between the grid and the platen, however, (Fig. 3) the lever n is not depressed. The stop abuts against the levers p, Q and the releasing rod 0 actuates the releasing and braking device.

In the illustrative embodiment a cam is used for obtaining the lead of the protective grid (Z; if desired, other devices may, of course, be employed which are actuated by the connectingrod 70 or the driving mechanism of the machine and serve the same purpose. Further, the driving mechanism for the protective grid is arranged at only one side of the machine in the illustrative embodiment; both sides may, however, be connected with the driving mechanism. Again, in the illustrative embodiment a pivoted catch Z is used for locking the driving mechanism of the protective frame (Z,-

this catch may be acted upon by a spring,

if desired, instead of by gravity. Likewise, it is possible to employ any other wellknown locking device which, as soon as the protective grid or its driving mechan sm has attained its highest point when movmg upward, is automatically unlocked by the mechanism for driving the grid.

I claim 1. In a platen-press of the character described, the combination with the frame, a platen fixed thereto, a rocking press-head for carrying the form and driving means mounted on the frame for rocking the presshead, of a guard movably mounted on the press-head and adapted to cover the gap between the platen and the rocking format the end of the downward movement of the latter, and mechanism mounted on the driving means and on the press-head and actuated by said driving means for imparting to the guard a leading motion as compared with that of the press-head during the last part of the downward motion of the latter, and a locking device controlled by said driving means for automatically locking said mechanism at the end of the downward movement of the presshead, whereby when the press-head begins to move upward, the guard moves upward withthe same.

2. In a platen-press of the character described, the combination with the frame, a platen fixed thereto, a rocking press-head for carrying the form, and driving means mounted on the frame for rocking the presshead, of a guard movably' mounted on the press-head and adapted to cover thegap between the platen and the rocking form at the end of the downward movement of the latter, and mechanism mount-ed onthedriving means and on the press-head and actuated by said driving means for imparting to the guard a leading motion as compared with that of the press-head during the last part of the downward motion of the latter, and a locking device controlled by said driving means for automatically locking said mechanism at the end of the downward movement of the press-head, whereby when the press-head begins to move upward, the guard moves upward with the same, the mechanism being automatically unlocked before the guard arrives at its highest position.

3. In a platen-press of the character described, the combination with the frame, a platen fixed thereto, a rocking press-head for carrying the form, and a connectingrod mounted on the frame for rocking the presshead, of a grid mounted to reciprocate vertically on the press-head, a two-armed lever fulcrumed on the presshead and having one arm pivotally connected to the grid, a roller carried by the end of the other arm, a cam mounted on the connecting-rod and adapted to control said roller and thereby rock said lever and drive said grid, a stop fixed on the connecting-rod, and a catch mounted on the press-head and adapted to coact with said stop for locking the roller in the upper position of the grid.

4. In a platen-press of the character described, the combination with the frame, a platen fixed thereto, a rocking press-head for carrying the form, and a connecting-rod mounted on the frame for rocking the presshead, of a grid mounted to reciprocate vertically on the press-head, a two-armed lever fulcrumed on the press-head and having one arm pivotally connected to the grid, a roller carried by the end of the other arm, a cam mounted on the connecting-rod and adapted to control said roller and thereby rock said lever and drive said grid, a stop fixed on the connecting-rod, and a catch mounted on the press-head and adapted to co-actwith said stop for locking the roller in the upper position of the grid; disconnecting means for throwing the press out of gear and braking the same, a second stop on the connecting-rod adapted to actuate the disconnecting means, a lever pivotally connected with the disconnecting means for removing the same out of the path of the second stop and adapted to be rocked by the grid at the end of the downward stroke of the same.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

MAX ROOKSTROH.

Witnesses PAUL ARRAs, ARTHUR GUBE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

